Automatic tow rope rewinder



March 29, 1966 J. c. HORNBY 3,242,895

AUTOMATIC TOW ROPE REWINDER Filed June 24, 1964 FIGI FIG.2 3 N '4 la/5WI I I E III" III" L \J I I I II m| IF IIIIIII R I I I I I i 91 l FIG?)I5 I: I I 4| 9 J" 'I II 22 I 36 V L4 I R I I w I F164 -jifi IW UnitedStates Patent Filed June 24, 1964, Ser; No. 377,649 6 Claims. Cl.114-235 This invention relates to a tow rope re-winding device forboats.

As is known, a tow rope device is attached to the rear end of a motorboat and serves to pull a water skier behind the motor boat.

Several such devices have been proposed. For instance, see US. Patent2,816,310, and Canadian Patent 600,526.

The device of the present invention is not only novel but it embodiesfeatures which make the device a very safe one and serve to curemanifest faults and weaknesses in the devices shown in the two patentsaforesaid as well as all other devices of which I am aware.

The bad features of the known devices are well known to skiers, the moreimportant of these beingand thus far not overcome or cured-that towlines often become fouled or tangled when the motor boat changes itsdirection. It is also well known that the stability of the boat isseriously affected, if not endangered, by the use of the present-daydevices.

The most important feature of my invention, and that which lends it somuch merit, is that the tow rope, at its forward end, is anchored to androlled on a drum which rides (slides) axially on a curved rod attachedto the rear (transom) of the motor boat to lie in a horizontal plane,the radius of curvature of the rod being such, and the rod being soattached to the transom, that the curved portion or arc of the rod liesbehind the engine and the centre of the arc lies in the longitudinalaxis of the boat at a distance forwardly of the engine but as close aspossible to the vertical axis (axis of rotation) on which the boathorizontally rotates when changing its direction of travel. This featureor principle provides stability to the motor boat at all times,regardless of the change of direction of the boat or of the relativeposition of the boat and the skier. In other words, the pulling force ofthe rope is always applied at a point along the longitudinal centre lineof the boat and at a point closer amidships than has hitherto beenattained by the known water skiing devices.

Thus, the advantages of this device are manifest, particularly in thatthey promote safety.

Another object or feature of the invention is that it provides a quickreleasing mechanism attaching the device to the boat. If at any time itis required that the motor be tilted out of the water, the skiing deviceof the invention can be released quickly by a sharp blow, say with onehand, applied to each securing point.

In the drawing, wherein like numerals of reference indicatecorresponding parts in various figures,

FIGURE 1 is a (more or less diagrammatic) plan view of the deviceattached to a conventional outboard motordriven water craft, the towcable being shown as almost completely wound around the drum;

FIGURE 2 is a side elevation of FIGURE 1;

FIGURE 3 is a rear view of the water craft, on an enlarged scale;

FIGURE 4 is a section on line 4-4 in FIGURE 3;

FIGURE 5 is a fragmentary section on line 5-5 in FIGURE 3;

FIGURE 6 is a fragmentary section on line 66 in FIGURE 3; and

FIGURE 7 is a section on line 77 in FIGURE 6.

Referring now by numerals to the drawing B shows a typical boatincluding a rear flat transom R. Releasably Patented Mar. 29, 1966mounted on the transom R, say by means to be described later, is asubstantially U-shaped supporting guide device D including two parallelside portions or members) and an intermediate curved member 11 ofrectangular or any other cross-section except circular. The radius ofcurvature of the member 11 and the distance between the curved member 11where it intersects the longitudinal axis of the boat and the transomare such that the centre of the curved member 11 is as close to thevertical axis of rotation of the boat, when carrying its intended load,as may possibly be determined. Such axis is shown as C. In changing itsorientation, the boat turns (pivots) on such vertical axis. Preferably,and as seen in FIGURE 1, stops W in the form of washers (say) welded tothe guide D limit the sliding movement of the drum N on the guide.

Slidably supported on the guideD, more particularly on its intermediatecurved portion or member 11 is a drum on which a cable F is adapted tobe wound. To the rear, free end of the cable F is attached a handle 14which may be of any kind, conventional or otherwise. Attached to thecable F, adjacent to the handle 14 is a stop 15 the function of whichwill be described later. The cable F, at its inner end, is Operativelyanchored to the drum so that the cable may be wound around the drum. Theinner end of the cable may be said to be resiliently attached to thedrum as will be apparent later.

The drum N may include a one-piece drum proper 30 formed to presentopposite flanges 16 and having its side walls 17 formed with alignedapertures 18. Retained within the aligned apertures is a two-piece core19, in effect forming a non-rotatable supporting shaft on which the drumproper is adapted to rotaterotating in one direction when the cable F isbeing unwound or'played out, and rotating in the opposite direction torewind the cable onto the drum.

Operatively connected between the rotatable drum proper 3i and the core19 are two coil springs 28A, the springs encircling the core and beingfixed or anchored at their opposite ends to the drum 30 and to the core19, respectively. The tension in the springs increases as the drumrotates on the core to play out the cable, the springs operating torewind the cable on the drum when the pull or tension on the end of thecable is relieved as when the skier has let go of the cable and thespeed of the watercraft has been sufficiently reduced.

As already stated, the drum is adapted to slide on the curved portion ofthe guide D. The two halves 19A 19A of the two-part core 19 are formedwith the two co-facing complementary notches (of any shape exceptcircular) defining, when both halves are locked into a core-formingrelationship, as clearly seen in FIGURE 6, a channel of cross-sectionother than circular adapted to slide over the correspondinglycross-sectioned portion 11 of the drum-supporting guide D. Preferablythe crosssection should be square.

The inner end of the cable is attached to one end of a rod 23 sliding inone wall (the front wall 31) of a tube 24 housed within a bore 25 formedthrough the drum. The rod 23 is riveted behind a disc or plunger 26sliding within the tube. A coil spring 28, encircling the rod 23, istensioned between the front wall 31 and the disc 26. The front wall 31is made to a diameter larger than that of the bore 25, so that it servesas a stop determining the longitudinal displacement of the tuberearwardly in the bore 25. A disc 33, of a diameter larger than that ofthe tube 24 and removably attached to the rear end wall of the tube 24serves, in conjunction with the front wall 31 of the member 24, toretain the tube in its operative position within the bore, and thereforeto lock the tube in operative position. The disc 33 is removablyattached to the rear end Wall of the tube 24- as by a nut 46 threadedonto a stud 47 anchored in the rear wall.

The spring 28 serves as a bufier or shock-absorbing member when thecable has been completely played out.

The tube 24 is utilized conveniently to lock the twopiece core 19 inoperative position within the drum N by providing on the periphery ofthe two-piece core a circumferentially extended raised portion or discformed with a peripheral groove 53 in which the tube 24 is received, asbest seen in FIGURE 7.

The cable automatically and gradually unwinds as the boat moves forwardand the resistance offered by the water to the forward movement of theskier exceeds the tension in the spring Attached to the core 19 is acable support in the form of a flat bar 35 slotted as at 36 and heldbehind the drum as by a pair of arms 37 secured to the core of the drum.Conveniently, the ends of the arms 37 are formed with a pair of fingers38 secured to the respective halves of the core as by screws 39.

Readily to detach the guide from the transom of the boat, the inner endsof the parallel members 10 of the guide are pivotally attached as byscrews 4% to brackets 41. Each such bracket 41 is provided with a slot42 merging into a circular hole or recess 43 of a diameter larger thanthe width of the slot 42. The bracket is attached to and suspended froma screw 45 attached to the transom as best seen in FIGURE 4.

Operation As the boat increases its speed (after the motor has, beenstarted), the resistance ofiered by the skier gradually causes the drumto rotateand to continue to rotate until the cable has been let out toits maximum length. However the drum, under the influence of its loadedspring, rewinds the cable when the pull on the cable has beensufficiently decreased as, for example, when the skier lets go of orreleases the cable and the speed of the boat has been sufficientlyreduced. This constitutes a very important safety feature of my devicesince once the skier has let go of the cable, and the speed of the boathas been sufficiently reduced, the cable is retrieved to the boat bybeing automatically rewound onto the drum. The trailing cable is thusprevented from constituting a hazard to the skier or to any one else orto any object in or near the water.

As will be readily appreciated, .the spring 28 acts as a buffer orshock-absorber as when the skis suddenly encounter a wave and a suddenthough temporary increase in resistance results.

As already stated, the axis of the cable, when in tension, bisects thelongitudinal axis of the boat or is coextensive therewith, according towhether the longitudinal axis'of the boat is at an angle to thelongitudinal axis of the tow rope as when the boat is in the. process ofnegotiating a turn, or the axis of the boat and the axis of the tow ropecoincide as when the boat is moving straight ahead.

If the boat is in the process of negotiating a turn, the axis of the towrope bisects the longitudinal axis of the boat at a point well ahead ofthe engine and as much as possible and, ideally, bisects thelongitudinal axis at the point on which the boat turns when changing itsdirection of travel.

As will be readily understood, the stop 15 serves to determine therotation of the drum N in its cable-rewinding operation (clockwise asseen in FIGURE 2) as the stop engages the cable support (flat bar) 35.

What I claim is:

1. In combination with a water craft having a horizontal rail positionedat a distance rearwar-dly of the transom of the water craft, said railhaving a non-circular cross-section, a core member mounted on said railfor longitudinal displacement thereon between two selected positions,said core member having a hole therethrough corresponding to the shapeof said rail to prevent axial rotation of said core member around saidrail, a drum supported on said core member for axial rotation relativethereto, spring means acting between said core member and said drum totend to maintain the core member and drum in a predetermined rotationalrelationship, and a cable wound on said drum having an endresiliently-anchored thereto and carrying a handle at its opposite endto be grasped by the skier, said rail including a transversely-disposedcurved middle portion the centre of the radius of which lies in thelongitudinal axis of the water craft at a distance forwardly of thetransom.

2. A combination as in claim 1, wherein a horizontal guide, supported bysaid drum rearwardly thereof and adjacent thereto, slidably supportssaid cable.

3. A combination as in claim 1, wherein said rail terminates inoppositely-disposed, parallel members to the ends of which are pivotallyattached supporting transomengaging brackets.

4. In combination with'a water craft having a horizontal rail positionedat the rear of said craft, a core member mounted on said rail forlongitudinal displacement therealong between two selected positions,said core member including means for preventing axial rotation of saidcore member around said rail, a drum supported on said core member foraxial rotation relative thereto, spring means acting between saidcoremember and said drum to tend to maintain the core member and drum in apredetermined rotational relationship, and a cable wound on said drum,said cable being connected to the drum at one end and carrying a handleat its opposite end to be grasped by a skier.

5. A combination as claimed in claim 4 including means resilientlyanchoring said one end of the cable to I the drum.

References Cited by the Examiner UNITED STATES PATENTS 12/1959 Force114-235 X 3/1961 Lang 114-235 MILTON BUCHLER, Primary Examiner. T. M.BLIX, Assistant Examiner.

1. IN COMBINATION WITH A WATER CRAFT HAVING A HORIZONTAL RAIL POSITIONEDAT A DISTANCE REARWARDLY OF THE TRANSOM OF THE WATER CRAFT, SAID RAILHAVING A NON-CIRCULAR CROSS-SECTION, A CORE MEMBER MOUNTED ON SAID RAILFOR LONGITUDINAL DISPLACEMENT THEREON BETWEEN TWO SELECTED POSITIONS,SAID CORE MEMBER HAVING A HOLE THERETHROUGH CORRESPONDING TO THE SHAPEOF SAID RAIL TO PREVENT AXIAL ROTATION OF SAID CORE MEMBER AROUND SAIDRAIL, A DRUM SUPPORTED ON SAID CORE MEMBER FOR AXIAL ROTATION RELATIVETHERETO, SPRING MEANS ACTING BETWEEN SAID CORE MEMBER AND SAID DRUM TOTEND TO MAINTAIN THE CORE MEMBER AND DRUM IN A PREDETERMINED ROTATIONALRELATIONSHIP, AND A CABLE WOUND ON SAID DRUM HAVING AN ENDRESILIENTLY-ANCHORED THERETO AND CARRYING A HANDLE AT ITS OPPOSITE ENDTO BE GRASPED BY THE SKIER, SAID RAIL INCLUDING A TRANSVERSELY-DISPOSEDCURVED MIDDLE PORTION THE CENTRE OF THE RADIUS OF WHICH LIES IN THELONGITUDINAL AXIS OF THE WATER CRAFT AT A DISTANCE FORWARDLY OF THETRANSOM.